A West Hempstead-based lawyer was charged in a securities fraud case that has led the U.S. Attorney's Office for the Southern District of Florida to convict six other alleged co-conspirators.

Mark Lubin was charged with a single count of conspiracy to unlawfully sell unregistered securities, Florida federal officials announced Wednesday. According to them, Lubin operated as a buyer, broker and attorney for various shell companies registered with the Securities and Exchange Commission as part of an elaborate fraud scheme.

Prosecutors said Lubin helped to support the fraudulent schemes, at times issuing opinion letters that suggested shares of the shell companies were not owned by affiliates, making them available for public investment.